Sildenafil (Including Viagra)

SILDENAFIL (INCLUDING VIAGRA)

Medicine Information

  • Ejaculation problems
  • Erectile dysfunction (impotence)
  • Male sexual problems
  • Priapism (painful erections)
  • Pulmonary hypertension
  • Relate (sex therapy): charity
  • Sexual Advice Association: charity
  • Sildenafil: forum
  • Viagra: forum

Sildenafil is a medicine used to treat erectile dysfunction. It increases blood flow to the penis to help men get an erection. At least two-thirds of men have improved erections after taking it.

Sildenafil is also sometimes used to treat pulmonary hypertension (high blood pressure in the blood vessels that supply the lungs).

This medicine is available on prescription and can also be bought from most pharmacies. It comes as tablets that you swallow, chewable tablets, and as a liquid that you drink.

  • It usually takes 30 to 60 minutes for sildenafil to work for erectile dysfunction. You can take it up to 4 hours before you want to have sex.
  • Taking sildenafil alone will not cause an erection. You need to be aroused for it to work.
  • The most common side effects are headaches, feeling sick, hot flushes and dizziness. Many men have no side effects or only mild ones.
  • It can be dangerous to take sildenafil if you also take medicines called nitrates (often given for chest pain). The combination can cause a dangerous fall in your blood pressure. If you’re not sure if you’re taking a nitrate, ask your doctor or pharmacist.
  • Sildenafil is called by the brand names Viagra (for erectile dysfunction) and Revatio (for pulmonary hypertension).

Sildenafil for erectile dysfunction (Viagra) can be taken by men aged 18 and over. It’s not for women or children.

Sildenafil for pulmonary hypertension (Revatio) can be taken by adults and children aged 1 and over.

Sildenafil is not suitable for some people.

Do not take sildenafil if you:

  • have had an allergic reaction to sildenafil (Viagra) or any other medicines in the past
  • are taking medicines called nitrates for chest pain
  • have a serious heart or liver problem
  • have recently had a stroke or a heart attack
  • have low blood pressure
  • have a rare inherited eye disease, such as retinitis pigmentosa

Check with your doctor before taking sildenafil if you:

  • have sickle cell anaemia (an abnormality of red blood cells), leukaemia (cancer of blood cells) or multiple myeloma (cancer of bone marrow)
  • have a deformity of your penis or Peyronie’s disease (curved penis)
  • have a heart problem. Your doctor should carefully check whether your heart can take the additional strain of having sex.
  • have a stomach ulcer or a bleeding problem like haemophilia

ON THE NHS

You can get sildenafil on the NHS if you have erectile dysfunction or pulmonary hypertension.

Branded versions of sildenafil such as Viagra are not available on the NHS, except in special circumstances.

PRIVATE PRESCRIPTION

You can also get sildenafil on a private prescription from your doctor. This means you’ll need to pay the full cost of the medicine.

Prices vary, but on average 4 tablets costs around £20.

FROM A PHARMACY

You can buy sildenafil from a pharmacy following a discussion with the pharmacist.

They’ll ask you some questions about your general health to make sure sildenafil is safe for you to take. You can also talk to them about side effects.

If the pharmacist has any concerns about whether sildenafil is safe for you, they may advise you to see your doctor.

ONLINE

You can buy sildenafil/Viagra over the internet. Be very careful if you do this as many websites sell fake medicines.

Online medicines are not always regulated and the ingredients in them can vary from one pack to another. They can cause unpleasant side effects or may not be suitable for you.

It’s best to see your doctor before buying medicines online. They know your medical history and can discuss whether you might benefit from treatment.

If you choose to buy sildenafil/Viagra over the internet, make sure:

  • any online pharmacy is registered with the General Pharmaceutical Council (GPhC)
  • any online doctor service is registered with the Care Quality Commission (CQC)
  • all doctors are registered with the General Medical Council (GMC)

It’s important to take it as advised by your doctor or pharmacist.

HOW MUCH WILL I TAKE FOR ERECTILE DYSFUNCTION?

Sildenafil tablets for erectile dysfunction come in different strengths ranging from 25mg to 100mg.

The usual dose is 50mg, when you need it (no more than once a day).

The dose can be increased to 100mg or decreased to 25mg depending on its effect.

Take sildenafil up to 4 hours before you want to have sex. For sildenafil to work properly, you’ll need to be sexually excited.

HOW MUCH WILL I TAKE FOR PULMONARY HYPERTENSION?

Sildenafil tablets for pulmonary hypertension come in 10mg and 20mg tablets.

The usual adult dose is 20mg taken 3 times a day.

Doses for children can range from 10mg to 20mg taken 3 times a day, depending on their weight.

HOW TO TAKE IT

Swallow tablets whole with a glass of water or juice (but not grapefruit juice).

For erectile dysfunction, it’s best to take sildenafil on an empty stomach. It may take longer to work if you take it with food.

LIQUID SILDENAFIL

If you or your child are taking sildenafil as a liquid, 1ml is usually the same as taking a 10mg tablet, but it’s important to always check the medicine label.

Liquid sildenafil will usually be made up for you by your pharmacist.

The medicine will come with a plastic syringe or spoon to help you take the right amount.

If you do not have a plastic syringe or spoon, ask your pharmacist for one. Do not use a kitchen teaspoon as it will not give the right amount.

WHAT IF I FORGET TO TAKE IT?

If you have pulmonary hypertension and you forget to take a dose of sildenafil, take it as soon as you remember and then continue as usual.

Never take 2 doses at the same time. Never take an extra dose to make up for a forgotten one.

If you often forget doses, it may help to set an alarm to remind you.

You could also ask your pharmacist for advice on other ways to help you remember to take your medicine.

WHAT IF I TAKE TOO MUCH?

Taking too much sildenafil by accident can cause unpleasant side effects, such as:

  • headaches
  • dizziness
  • indigestion
  • blocked nose
  • altered vision

Talk to your doctor if you have taken too much sildenafil and you’re worried about these side effects.

Like all medicines, sildenafil can cause side effects in some people. Many people have no side effects or only minor ones.

COMMON SIDE EFFECTS

Common side effects happen in more than 1 in 100 people.

If you get these side effects, keep taking the medicine, but tell your doctor or pharmacist if these side effects bother you or do not go away:

  • headaches
  • feeling sick
  • hot flushes, including facial flushing
  • indigestion
  • a colour tinge to your vision or blurred vision
  • stuffy nose
  • dizziness

SERIOUS SIDE EFFECTS

Serious side effects are rare and happen in less than 1 in 1,000 people.

Stop taking sildenafil and call a doctor straight away if you get:

  • chest pains – if this happens during or after sex, get into a semi-sitting position and try to relax; do not use nitrates to treat your chest pain
  • prolonged and sometimes painful erections – if you have an erection that lasts for more than 4 hours, contact a doctor immediately
  • a sudden decrease or loss of vision
  • a serious skin reaction – symptoms may include fever, severe peeling and swelling of the skin, blistering of the mouth, genitals and around the eyes
  • seizures

Serious allergic reaction

In rare cases, it’s possible to have a serious allergic reaction (anaphylaxis) to sildenafil.

CALL 999 OR GO TO A&E IF:

  • you get a skin rash that may include itchy, red, swollen, blistered or peeling skin
  • you’re wheezing
  • you get tightness in the chest or throat
  • you have trouble breathing or talking
  • your mouth, face, lips, tongue or throat start swelling

You could be having a serious allergic reaction and may need immediate treatment in hospital.

These are not all the side effects of sildenafil.

For a full list, see the leaflet inside your medicines packet.

You can report any suspected side effect to the UK safety scheme.

Sildenafil is not recommended in pregnancy and while breastfeeding.

TELL YOUR DOCTOR IF YOU’RE:

  • trying to get pregnant
  • pregnant
  • breastfeeding

Some medicines do not mix well with sildenafil.

Tell your doctor if you’re taking these medicines before you start sildenafil:

  • nitrates for chest pain
  • riociguat for pulmonary hypertension
  • recreational drugs called poppers, such as amyl nitrite

MIXING SILDENAFIL WITH HERBAL REMEDIES AND SUPPLEMENTS

Some complementary therapies may have ingredients that could interfere with sildenafil and cause side effects.

IMPORTANT

Tell your doctor or pharmacist if you’re taking any other medicines, including herbal remedies, vitamins or supplements.

Simeticone works by bringing together the small gas bubbles in your gut to form bigger bubbles. The wind can then leave your body more easily (by burping or farting).

Simeticone does not pass into your blood. It stays in the gut until it leaves your body in poo.

Simeticone usually starts to work within about 30 minutes. Liquids or chewable tablets may work slightly more quickly than non-chewable tablets or capsules.

For colic, you may need to give it to your baby for a few days to see the full benefits.

The same applies if you’re taking it for irritable bowel syndrome (IBS) or other long-term medical conditions that cause bloating.

Speak to a doctor or your health visitor if the symptoms get worse or do not improve within a few days.

Simeticone is generally a safe medicine, so there’s no strict limit on how long you or your baby can take it for. However, most people will only need to take it occasionally, or over a short period of time.

Talk to a doctor if you’ve been taking simeticone regularly for more than 14 days.

It’s safe to continue giving simeticone to your baby for colic for several weeks, but talk to a doctor or health visitor if your baby’s symptoms do not improve or if they get worse.

If you are taking simeticone to treat bloating caused by an ongoing condition such as irritable bowel syndrome (IBS), there’s no harm in taking it long term. Just make sure you tell a doctor if you are taking it.

For colic, there’s not much scientific evidence that simeticone really works.

In studies where simeticone was used alongside a dummy treatment (placebo), there was not much difference between them.

We cannot be certain that it really works for bloating, trapped wind or indigestion either.

In studies, there was not much difference between taking simeticone and antacids together compared to taking antacids on their own.

One theory is that your symptoms (or your baby’s) are not actually due to trapped wind. They may be caused by something else.

Simeticone is not the same as dimeticone.

Dimeticone is a substance found in many cosmetics and medicines, including nappy rash creams and treatments for headlice.

Simeticone is “activated dimeticone”. It contains dimeticone, mixed with silicon dioxide or silica gel. This makes the medicine work better to get rid of the wind in your gut.

There are several other medicines that you can try for trapped wind. Ask a pharmacist for advice, particularly if it’s for a baby.

Gripe water (which contains dill seed oil) works by breaking down trapped gas bubbles. It can be used to treat colic in babies aged 1 month and above.

However, like simeticone, there’s not much evidence that it works for colic.

There are other medicines for treating colic, bloating or trapped wind that work differently to simeticone and gripe water.

These include:

  • dicycloverine and peppermint oil to reduce spasms in the stomach
  • Colief to help break down the natural sugars in milk (lactose)
  • activated charcoal to trap gas bubbles
  • sodium bicarbonate and antacids to neutralise stomach acid

Simeticone is not affected by alcohol.

However, if you’re taking a medicine that contains simeticone combined with other ingredients, read the leaflet to check it is safe to drink alcohol.

Ask a pharmacist if you’re not sure.

There are no foods or drinks that you need to avoid when taking simeticone.

However, if you’re bothered by bloating or trapped wind, it may help to:

  • avoid or cut down on foods that may cause bloating such as onions, cabbage, sprouts, turnips, beans and lentils
  • avoid or cut down on fatty and spicy foods
  • have fewer fizzy drinks
  • reduce caffeine (found in coffee, tea, energy drinks and chocolate)

Find out more about things you can do to help bloating and foods to help your digestion.

There are several things you can do to help prevent bloating and trapped wind.

It’s a good idea to:

  • avoid foods that are known to cause gas, including onions, cabbage, turnips, beans and lentils
  • avoid or cut down on fatty and spicy foods
  • avoid chewing gum
  • avoid using straws for drinking
  • reduce or avoid drinking fizzy drinks and drinks containing caffeine
  • eat slowly
  • eat more fibre to prevent constipation. If you find high-fibre foods such as cereal or grains cause bloating, eat more fruits and vegetables instead to ensure you get enough fibre.
  • quit smoking (if you smoke)

Talk to your health visitor for advice on soothing a baby with colic.

They may suggest trying things such as:

  • sitting or holding your baby upright when feeding them, to stop them from swallowing air
  • massaging your baby’s tummy in a clockwise direction
  • winding your baby during and after feeds, if needed
  • changing the brand of formula or using slow-flow or anti-colic teats if you give your baby a bottle
  • gently rocking your baby over your shoulder, or in their basket or crib, or pushing them in their pram
  • giving your baby a warm bath

You may have heard about trying:

  • herbal and probiotic supplements
  • changing your diet if you’re breastfeeding
  • using gentle pressure on your baby’s spine (spinal manipulation) or skull (cranial osteopathy)

However, there’s very little evidence these things work. Speak to your health visitor for advice and support.